3947734561 has 9 divisors (see below), whose sum is σ = 4001156211. Its totient is φ = 3895019352.

The previous prime is 3947734529. The next prime is 3947734579. The reversal of 3947734561 is 1654377493.

It is a happy number.

The square root of 3947734561 is 62831.

It is a perfect power (a square), and thus also a powerful number.

3947734561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 2438878225 + 1508856336 = 49385^2 + 38844^2 .

It is not a de Polignac number, because 3947734561 - 2⁵ = 3947734529 is a prime.

It is a super-2 number, since 2×3947734561² = 31169216328227725442, which contains 22 as substring.

It is a Duffinian number.

Its product of digits (1905120) is a multiple of the sum of its prime divisors (840).

It is not an unprimeable number, because it can be changed into a prime (3947734961) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 5214595 + ... + 5215351.

Almost surely, 2^3947734561 is an apocalyptic number.

3947734561 is the 62831-st square number.

3947734561 is the 31416-th centered octagonal number.

It is an amenable number.

3947734561 is a deficient number, since it is larger than the sum of its proper divisors (53421650).

3947734561 is an frugal number, since it uses more digits than its factorization.

3947734561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1680 (or 840 counting only the distinct ones).

The product of its digits is 1905120, while the sum is 49.

The cubic root of 3947734561 is about 1580.4568674270.

Multiplying 3947734561 by its sum of digits (49), we get a square (193438993489 = 439817²).

The spelling of 3947734561 in words is "three billion, nine hundred forty-seven million, seven hundred thirty-four thousand, five hundred sixty-one".